Dopaminergic neuromodulation of semantic processing: A 4-T fMRI study with levodopa
Data(s) |
2009
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Resumo |
There is emerging evidence that alterations in dopaminergic transmission can influence semantic processing, yet the neural mechanisms involved are unknown. The influence of levodopa (L-DOPA) on semantic priming was investigated in healthy individuals (n=20) using event-related functional magnetic resonance imaging with a randomized, double-blind crossover design. Critical prime-target pairs consisted of a lexical ambiguity prime and 1) a target related to the dominant meaning of the prime (e.g., bank-money), 2) a target related to the subordinate meaning (e.g., fence-sword), or 3) an unrelated target (e.g., ball-desk). Behavioral data showed that both dominant and subordinate meanings were primed on placebo. In contrast, there was preserved priming of dominant meanings and no significant priming of subordinate meanings on L-DOPA, the latter associated with decreased anterior cingulate and dorsal prefrontal cortex activity. Dominant meaning activation on L-DOPA was associated with increased activity in the left rolandic operculum and left middle temporal gyrus. These findings suggest that L-DOPA enhances frequency-based semantic focus via prefrontal and temporal modulation of automatic semantic priming and through engagement of anterior cingulate mechanisms supporting attentional/controlled priming. |
Identificador | |
Publicador |
Oxford University Press |
Relação |
DOI:10.1093/cercor/bhp017 Copland, D. A., McMahon, K. L., Silburn, P. A., & de Zubicaray, Greig I. (2009) Dopaminergic neuromodulation of semantic processing: A 4-T fMRI study with levodopa. Cerebral Cortex, 19(11), pp. 2651-2658. http://purl.org/au-research/grants/ARC/DP0452264 |
Direitos |
Copyright 2009 The Author |
Fonte |
Faculty of Health; Institute of Health and Biomedical Innovation |
Palavras-Chave | #Brain imaging #Dopamine #FMRI #Language #Lexical ambiguity #Semantic priming |
Tipo |
Journal Article |